Intel i7 CPU 960 @ 3.20GHz, 3201 Mhz, 4 Core(s), 8 Logical Processor(s)

Windows 7 pro

Hi all, I recently bought the World Instrument package and I find that the stringed instruments are a full semitone sharp... I press C but C sharp is played and shown on the virtual keyboard. How do I set this to actually play a C when I depress the C key please?

Thank you.

Rob.